Compressor



Dec. 19, 195o s. J, SSSSSS EN 2,535,019

MMMMMMM 0R Patented Dec. 19, 1950 CMPEESS'OB Sverre Johan Steensen, V.Aker, near Oslo, Norway Application -October 29, i945, Serial No.625,318 in Norwayaprilv 29, 1942 Section 1, llublic Law 690, August 8,1946 Patent expires April .29, 1962 1 Claim.

This invention relates to compressors with a piston, which moveseccentrically in relation to the interior cylinder wall, so that itscontacting point against the cylinder wall moves constantly around thesame. The ordinary construction is that the piston is fastened to ashaft which is located eccentrically relatively to the cylinder and isdriven around in the same by means oi' a motor. Consequently the shaftmust guided tightly through one head of the cylinder.

vThis construction requires an extreivrnanuiaeture, and already after avery little tear oi the cooperating lsurfaces of piston and cyl'- lyexact inder, a leakage will take place, and the eilicicncy of thecompressor will be decreased. Moreover, care must be taken for atightening by stuillng box at the place where the piston shaft .passesout from the cylinder. Also this will give rise to leakage.

The present invention has for its purpose a construction which is notaillicted with the drawbacks mentioned above, and which is particularlyintended to be used in refrigerator cabinets for domestic use. Theinterior space of the cornpressor itself is hermetically sealed, whereasthe motor is located outside the sealed system of compartment andconduits.

It has a simple and eicient execution and consequently is very cheap inmanufacture and operation. This is obtained by the use of a strongmagnet which rotates in relation to the non-magnetic cylinder outsidethe latter and thereby causes the contacting point of the magneticpiston to move as stated above.

Thereby a cylindric piston may be placed loosely into a cylinder with alarger diameter, a partition directed towards the center being ixed onthe interior cylinder wall and meshing in a radial groove correspondingthereto and made in the piston in order to separate the suction sidefrom the pressure side. Further, a preferably annular rotating magnetwith pole shoes is arranged, said shoes travelling with a quite smallmargin around in the stationary cylinder.

Consequently there are no shafts or eccentrics i and moreover no exactadaptation between the curved surfaces of the piston and the cylinder isrequired. The end faces of the cylinder may simply be adapted to eachother by placing the top and bottom of the cylinder against the endsurface of the piston and by soldering them to the periphery of thecylinder casing.

During the rolling or sliding of the piston against the cylinder wallthe piston is pressed against this wall and will always provide a good 2tightening contrary vto whatis the case when the piston is journaledaround a pin, because in such a oase it is always necessary to arrange aSmall distance which will gradually increase during .the use.

Further it is not necessary to let the said curved surfaces becircle-cylindrical surfaces. r-hey can very `well depart from thisshape. although this 4would be less suitable owing to the practicalmanufacture.

Another embodiment, ywherein the rotor in known manner rotates on a pinarranged eccentrically in the interior of the cylinder and provided withone or `more partitions guided radially in the vpiston and beingmaintained constantly in contact ywith the cylinder wall, may consist inthe rotor oi non-magnetic material rotating loosely on the eccentric pinand the partitions of magnetic material travelling loosely in theirgrooves acted upon by corresponding rotating magnets arranged outsidethe apparatus. Also this embodiment permits an hermetical sealing but isnevertheless less suitable.

In the drawing the two embodiments mentioned above are illustrated. Fig.1 is a cross section through the compressor, and Fig. 2 a correspondingaxial longitude section.

The cylinder wall which is made of non-magnetic material is for instancea thin bronze pipe, to which is soldered the endwalls 2, 2 which may bemade of steel. One endwall is first soldered fast, whereafter the piston4 of magnetic material and with a somewhat less diameter is inserted.Then the other wall is placed in position until it is in contact withthe piston and is soldered fast in this position. Thereby the compressoritself is ready-mounted.

As will be seen from Fig. 1 the piston, which may have 3 4 mm, lessdiameter than the cylinder l, and lies loosely within the same, may rollor slide along the inner wall surface of the cylinder, it being coupledtogether with the cylinder only by the xed wing 3, which forms apartition between the suction and pressure side of the compressor. Thiswing 3 is fastened to the end-faces of the cylinder. l

The ports 5 and 6 represent the suction and pressure channels, dependentupon the direction of rotation.

Around the cylinder a strong magnet 8 is mounted on a disk 9, which isfastened to the motorshaft IIJ, so that it rotates around the cylinder Iwith a quite small intermediary space, for instance 0.1 mm. The poleshoes I3 and I4 of the magnet attract the piston 4, so that it willcontact strongly against the cylinderwall, and the contacting point willmove around according as the magnet rotates.

In this manner two separate compartments are formed, a suction and apressure compartment.

These compartments increase or decrease in volume according as themagnet rotates, and the contacting point adjacent to the pole shoes ofthe magnet moves along the periphery, whereby the enclosed gas passes inthrough one and out from the other one of the ports 5 and 6. Theinterior of the compressor of course must be supplied with oil forlubricating and tightening the surfaces. The magnet may be an electricmagnet with sliding contacts or a permanent magnet.

Of course not the Whole piston 4 need be of magnetic material. It issufcient that only an exterior cylindric ring is made of such amaterial, 01 the piston may be annular.

By very strong magnets it might occur' that the pole-shoes attract thepiston so strongly against the cylinderwall, that this in spite of theinsignicant sliding may give rise to tear or to deformation of thethin-walled cylinder. This may be avoided by arranging inside thecylinder, as shown in Fig. 1, a stationary concentric pin Il and byproviding the piston with a bore ll, which is concentric with the pistonbut eccentric to the cylinder, whereby the attracting force of themagnet will be taken up by the pin I l which in such case must be madeexactly.

Besides, it is obvious that the magnet or magnets rotating around thepump housing, may be replaced by a plurality of stationaryelectromagnets arranged around the housing and the current of which isclosed in succession, so that a rotary magnet eld is obtained.

I claim:

A compressor comprising a pump housing having an interior cylindricalspace, a cylindrical rotor piston of a diameter diierent from that ofinterior space of the housing and located loosely and eccentricallywithin the housing, said piston being at least partly of magnetizablematerial, means outside the housing for producing a rotary eld ofmagnetic forces to cause the piston to contact at any time with saidwall along an axially directed straight contacting line in rolling alongsaid wall with the contacting line travelling constantly around on thewall in accordance with the rotation of said magnetic eld, an inlet portfor the medium to be compressed, an outlet port for the compressedmedium, and a partition arranged between the inlet and outlet ports soas to separate at any time the suction space of the pump from thecompression space.

SVERRE JOHAN STEENSEN.

REFERENCES CITED The following references are of record in the iie ofthis patent:

UNITED STATES PATENTS Number Name Date 229,592 Drawbaugh July 6, 18801,766,872 Berglund June 24, 1930 2,161,374 Moineau June 6, 19392,399,856 Coger May 7, 1946 FOREIGN PATENTS Number Country Date 762,483France Jan. 22, 1934

